Getty Images Europe It's an endless debate, and a matter of great pride in both cities. Which of the world's two most financialised, globalisation-cheering megacities can reasonably be described as the world's capital?

One hundred and fifty years ago, the answer was indisputably London. Fifty years ago, the answer was indisputably New York. Now? Well it's not so clear. Here's Business Insider UK's best case that it's London, not New York, that deserves the crown.

It's One Of The World's Financial Capitals

In terms of stock exchanges, calling London the world's financial capital looks ludicrous. The London Stock Exchange isn't even the second-largest stock exchange in the world after the New York Stock Exchange. It's the fourth (after the Nasdaq and Tokyo).

But this is totally unfair to London: The volume of equities trading done on the London Stock Exchange doesn't capture at all equities trading done in any one place — just the ones local to that economy. So of course London's stock exchange is smaller than New York's: the UK's economy is much smaller than that of the US. But we're comparing the cities here, not the countries.

So it's good to look at a more international measure of finance: currency markets. In terms of foreign exchange market turnover, the UK isn't just the leader, it's still gaining ground, according to the Bank of International Settlements. In 1998, 32.6% of the world's forex trading was done in the UK (almost all of which takes place in London), against 18.3% in the US. By 2013, the UK had grown to make up 40.9% of the global market, seeing a daily average of $2.73 trillion in turnover. Every day.

That's not entirely surprising when you look at London's demographic makeup. Three million of London's 8 million inhabitants were born outside of the UK. In fact, the non-UK born population makes up 105% of the city's population growth between the 2001 and 2011 censuses. (Why 105%? Because native Brits left, causing negative growth, and the immigrants more than eclipsed that.)

The number of people moving to the UK from the rest of Europe has increased significantly. In 2007-2008, 15,400 Italians registered to work in the UK, a figure that was up to 44,110 by 2013. Europe's young workforce is increasingly migrating to the UK (where its workers don't need visas to live and work), and a huge number seek out London. One of the most well-educated generations in history is streaming to London to live and work, and that's an enormous benefit to the city.

And Everyone Wants To Live Here, Too

London reigns at the top of Knight Frank's global wealth report in 2014. Endless anecdotes in the reports show exactly where the world's wealthiest people want to own homes, and the British capital comes out ahead of New York.

The cost of buying and renting is something that makes Londoners want to weep: but it's a side effect of the city's incredible success.

In 2012-2013, 49% of buyers in London's prime central market were not British, illustrating the huge demand from abroad. And they're not just buying to hold property as an investment: Only 28% of buyers live outside the UK, showing that a huge number of international buyers want to live in the city.

It's The Capital Of Digital Media

The two biggest English-language newspaper websites in the world are London-based British organisations. The Daily Mail's Mail Online and The Guardian's website have broken into first and second place, according to comScore's traffic figures. That's even accounting for the fact that New York-based newspapers have a far bigger native American audience than London-based newspapers can find in the UK.

A Deloitte survey puts London not only as the world's leader of highly skilled workers in media (particularly digital media), but as one of the areas in which it is extending a lead over the others. Check out the chart above. The report suggests that although US cities take the lead in terms of film and TV, the London is way out ahead in terms of digital media.

And The Capital Of Culture

According to Japan's Institute for Urban Strategies, London takes a commanding lead over New York (and every other major city) on cultural grounds. That is based on a blend of cultural resources, facilities for visitors, and how trendsetting the city is.

The Tall Ship Tectona, built in India in 1929, is moored outside the Old Royal Naval College at Greenwich, the location of one of London's Unesco world heritage sites. REUTERS/Suzanne Plunkett

Part of this stems from a history that New York simply can't match: in the 19th century, it became only the second city since the fall of the Roman Empire to reach a population of over one million. Attractions like Westminster Hall (the great hall of the UK's parliament) are almost twice as old as European colonization in the Americas, and four times older than the US as a country.

It's not just British culture that is on offer. In GfK's survey of more than 5,000 people who visited some of the world's biggest cities, London ranks highest when visitors are asked whether they can "find people who appreciate my culture and with whom I could easily fit in."

Popular from BI Prime

Close iconTwo crossed lines that form an 'X'. It indicates a way to close an interaction, or dismiss a notification.Check mark iconA check mark. It indicates a confirmation of your intended interaction.